Abstract The aim of this work was to evaluate the microbiological and physicochemical qualities of sour cassava starch and cassava bagasse produced during cassava agroindustry in order to evaluate their potential for use in food. All samples were kindly provided by family farmers producers from the region of Cará, in town of Bela Vista de Goiás, Brazil. All of sour cassava starch samples showed microbial counts within the values established by the current legislation. Drying process of raw cassava bagasse to produce the bran was sufficient to reduce the mold and yeast counts (from 1.9x103 to 3.5x101 CFU g -1) and of total coliform counts (from 2.1x103 to 2.4x102 MPN 100 mL-1), and also eliminated the contamination by coliforms at 45 ° C and Bacillus cereus. Carbohydrate contents of all sour cassava starch samples ranged from 99.64 to 99.75 g 100g-1. These results indicated that the sour cassava starch presented high degree of purity, and extraction process was efficient. Bran sample showed high carbohydrate (96.94 g 100g-1) and dietary fiber (22.58 g 100g-1) contents. High dietary fiber content suggests the use of bran as raw material to increase the availability of fiber in food products, increasing its nutritional quality.